Field of the Invention
In one of its aspects, the present invention relates to a fluid treatment system. In another of its aspects, the present invention relates to a cleaning apparatus. In yet another of its aspects, the present invention relates to a radiation source module containing the cleaning system. In another of its aspects, the present invention relates to a method of removing fouling materials from an exterior surface of a radiation source assembly. Other aspects of the invention will become apparent to those of skill in the art upon reviewing the present specification.
Description of the Prior Art
Fluid treatment systems are known generally in the art.
For example, U.S. Pat. Nos. 4,482,809, 4,872,980 and 5,006,244 [all in the name of Maarschalkerweerd and hereinafter referred to as the Maarschalkerweerd #1 Patents] all describe gravity fed fluid treatment systems which employ ultraviolet (UV) radiation.
Such systems include an array of UV lamp frames which include several UV lamps each of which are mounted within sleeves which extend between and are supported by a pair of legs which are attached to a cross-piece. The so-supported sleeves (containing the UV lamps) are immersed into a fluid to be treated which is then irradiated as required. The amount of radiation to which the fluid is exposed is determined by the proximity of the fluid to the lamps, the output wattage of the lamps and the fluid's flow rate past the lamps. Typically, one or more UV sensors may be employed to monitor the UV output of the lamps and the fluid level is typically controlled, to some extent, downstream of the treatment device by means of level gates or the like.
In recent years, there has been interest in the so-called “transverse-to-flow” fluid treatment systems. In these systems, the radiation source is disposed in the fluid to be treated in a manner such that the longitudinal axis of the radiation source is in a transverse (e.g., orthogonal vertical orientation of the radiation sources) relationship with respect to the direction of fluid flow past the radiation source. See, for example, any one of:
International Publication Number WO 2004/000735 [Traubenberg et al.];
International Publication Number WO 2008/055344 [Ma et al.];
International Publication Number WO 2008/019490 [Traubenberg et al.];
U.S. Pat. No. 7,408,174 [From et al.]; and
U.S. provisional patent application Ser. No. 61/193,686 [Penhale et al.], filed Dec. 16, 2008.
Depending on the quality of the fluid which is being treated, the sleeves surrounding the UV lamps periodically become fouled with foreign materials, inhibiting their ability to transmit UV radiation to the fluid. For a given installation, the occurrence of such fouling may be determined from historical operating data or by measurements from the UV sensors. Once fouling has reached a certain point, the sleeves must be cleaned to remove the fouling materials and optimize system performance.
Regardless of whether the UV lamp modules are employed in an open channel system (e.g., such as the one described and illustrated in Maarschalkerweerd #1 Patents) or a tranverse to flow system as described above, one or more of the modules may be removed while the system continues to operate, and the removed frames may be immersed in a bath of suitable cleaning solution (e.g., a mild acid) which may be air-agitated to remove fouling materials. This practice was regarded by many in the field as inefficient, labourious and inconvenient.
In many cases, once installed, one of the largest maintenance costs associated with prior art fluid treatment systems is often the cost of cleaning the sleeves about the radiation sources.
U.S. Pat. Nos. 5,418,370, 5,539,210 and RE36,896 [all in the name of Maarschalkerweerd and hereinafter referred to as the Maarschalkerweerd #2 Patents] all describe an improved cleaning system, particularly advantageous for use in fluid treatment systems which employ UV radiation. Generally, the cleaning system comprises cleaning sleeves, each cleaning sleeve engaging a portion of the exterior of a radiation source assembly including a radiation source (e.g., a UV lamp). The cleaning sleeve is movable along the surface of the radiation source assembly. The cleaning sleeve includes a chamber in contact with the exterior surface of the radiation source assembly. The chamber is supplied with a cleaning fluid suitable for removing undesired materials from the exterior surface of the radiation source assembly.
The cleaning system described in the Maarschalkerweerd #2 Patents represented a significant advance in the art, particularly in that it facilitated in situ cleaning of the radiation source assembly without the need to remove the module(s) during operation of the fluid treatment system. However, when it becomes necessary to replace or replenish the cleaning fluid in the chamber of the cleaning sleeve, it is necessary to remove the module of radiation sources assemblies to which the cleaning sleeves are engaged and then manually fill the chamber of the cleaning sleeve with cleaning fluid.
Accordingly, it would be desirable to have a cleaning system in which it is possible to replace or replenish the cleaning fluid without the need to remove the module or radiation sources assemblies to which the cleaning sleeves are engaged.